Erosion resistant metal silicate coatings

ABSTRACT

Disclosed are rare earth metal containing silicate coatings, coated articles (e.g., heaters and susceptors) or bodies of articles and methods of coating such articles with a rare earth metal containing silicate coating.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a Divisional Application of U.S. Non Provisionalapplication Ser. No. 16/444,701, filed Jun. 19, 2019, which claims thebenefit of U.S. Provisional application No. 62/686,409, filed Jun. 18,2018, the disclosure of which is hereby incorporated by reference hereinin its entirety.

TECHNICAL FIELD

Embodiments of the disclosure relate to rare earth metal containingsilicate coatings, coated articles (e.g., heaters and susceptors) orbodies of articles and methods of coating such articles with a rareearth metal containing silicate coating.

BACKGROUND

Susceptors and heaters are important components in semiconductorprocessing chambers, for example, because they hold substrates duringcoating processes and/or implement surface modifications of substratesthrough various heating processes. Depending on the nature of aparticular process step, susceptors and heaters typically operate attemperatures of about 400° C. or higher while coming into contact withprocess gases. Upon cooling, the process gases may sublimate on thesusceptors and heaters causing a buildup of unwanted residue that may bereleased as particulates during a subsequent process step. To minimizesuch buildup and particle generation, the susceptors and heaters,together with other components in the process chamber, are subjected toin-situ chamber cleaning typically using various plasma chemistries(e.g., fluorine-based plasmas).

Susceptors and heaters are subject to surface contamination anddeposition by reactive process gases, which causes process drift (e.g.,in temperature control) over time. In addition, the materials generallyused to form susceptors and heaters are subject to erosion by plasmas(e.g., fluorine-containing plasmas) at temperatures of about 400° C. orhigher.

To protect susceptors and heaters it is desirable to coat thesecomponents with a plasma resistant coating. However, known plasmaresistant coatings are ineffective to protect these components at hightemperatures of about 400° C. or higher, or more particularly, of about700° C. or higher. For example, traditional plasma resistant coatingsformed by plasma spray (PS) processes do not provide good adhesion toSiC, TaC or AlN at high temperatures. Accordingly, there is a need forplasma resistant coatings that have good adhesion to susceptors andheaters, that do not affect the heating properties of the susceptors andheaters and that do not delaminate or erode in the presence of plasmasat temperatures of about 400° C. or higher.

SUMMARY

Embodiments herein relate to an article comprising a body; and a rareearth metal containing silicate coating on a surface of the body, therare earth metal containing silicate coating having a thickness of about3 nm to about 250 μm, wherein the rare earth metal containing silicatecoating comprises at least one of yttrium monosilicate (Y₂SiO₅), yttriumdisilicate (Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅), erbium disilicate(Er₂Si₂O₇), tantalum monosilicate (Ta₂SiO₅), tantalum disilicate(Ta₂Si₂O₇), iridium monosilicate (Ir₂SiO₅), iridium disilicate(Ir₂Si₂O₇), rhodium monosilicate (Rh₂SiO₅), rhodium disilicate(Rh₂Si₂O₇), lanthanum monosilicate (La₂SiO₅), lanthanum disilicate(La₂Si₂O₇), lutetium monosilicate (Lu₂SiO₅), lutetium disilicate(Lu₂Si₂O₇), scandium monosilicate (Sc₂SiO₅), scandium disilicate(Sc₂Si₂O₇), gadolinium monosilicate (Gd₂SiO₅), gadolinium disilicate(Gd₂Si₂O₇), samarium monosilicate (Sm₂SiO₅), samarium disilicate(Sm₂Si₂O₇), dysprosium monosilicate (Dy₂SiO₅), dysprosium disilicate(Dy₂Si₂O₇) and combinations thereof.

Embodiments described herein further relate to a method comprisingperforming a deposition process to deposit a rare earth metal containingsilicate coating on a surface of a chamber component for a processingchamber, wherein the rare earth metal containing silicate coating has athickness of about 5 nm to about 250 μm, and optionally, performing aPVD or PEPVD deposition process to deposit a thick rare earth metalsilicate layer above or below the rare earth metal containing silicatecoating, and wherein the rare earth metal containing silicate coatingcomprises at least one of yttrium monosilicate (Y₂SiO₅), yttriumdisilicate (Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅), erbium disilicate(Er₂Si₂O₇), tantalum monosilicate (Ta₂SiO₅), tantalum disilicate(Ta₂Si₂O₇), iridium monosilicate (Ir₂SiO₅), iridium disilicate(Ir₂Si₂O₇), rhodium monosilicate (Rh₂SiO₅), rhodium disilicate(Rh₂Si₂O₇), lanthanum monosilicate (La₂SiO₅), lanthanum disilicate(La₂Si₂O₇), lutetium monosilicate (Lu₂SiO₅), lutetium disilicate(Lu₂Si₂O₇), scandium monosilicate (Sc₂SiO₅), scandium disilicate(Sc₂Si₂O₇), gadolinium monosilicate (Gd₂SiO₅), gadolinium disilicate(Gd₂Si₂O₇), samarium monosilicate (Sm₂SiO₅), samarium disilicate(Sm₂Si₂O₇), dysprosium monosilicate (Dy₂SiO₅), dysprosium disilicate(Dy₂Si₂O₇) and combinations thereof.

Embodiments described herein further relate to a method comprisingperforming an atomic layer deposition process to deposit a rare earthmetal containing silicate coating on a surface of a heater comprisingaluminum nitride or a susceptor comprising graphite coated with siliconcarbide, tantalum carbide or a combination thereof; and optionally,performing a PVD or PEPVD deposition process to deposit a thick rareearth metal silicate layer above or below the rare earth metalcontaining silicate coating, wherein the rare earth metal containingsilicate coating has a thickness of about 3 nm to about 20 μm, and

wherein the rare earth metal comprises at least one of yttrium, erbium,tantalum, iridium, rhodium, lanthanum, lutetium, scandium, gadolinium,samarium, dysprosium, and combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that differentreferences to “an” or “one” embodiment in this disclosure are notnecessarily to the same embodiment, and such references mean at leastone.

FIG. 1 depicts a sectional view of a processing chamber.

FIG. 2A depicts a heater assembly with components having a rare earthmetal containing silicate coating in accordance with embodiments.

FIG. 2B depicts a susceptor assembly with components having a rare earthmetal containing silicate coating in accordance with embodiments.

FIG. 3A depicts one embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 3B depicts another embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 3C depicts another embodiment of a deposition process in accordancewith an atomic layer deposition technique as described herein.

FIG. 3D depicts another embodiment of a deposition process in accordancewith a combination of a physical vapor deposition over atomic layerdeposition technique as described herein.

FIG. 4A illustrates a method for creating a plasma resistant coatingusing atomic layer deposition as described herein.

FIG. 4B illustrates a method for creating a plasma resistant coatingusing atomic layer deposition as described herein.

DETAILED DESCRIPTION

Embodiments of the disclosure relate to rare earth silicate coatings,coated articles (e.g., chamber components such as susceptors andheaters) having a rare earth metal containing silicate coating, methodsof forming such coated articles with a rare earth metal containingsilicate coating and methods of use of such coatings and coatedarticles. The rare earth metal containing silicate coating may have asimilar thermal expansion as an underlying material of a body of thearticle (e.g., a heater or susceptor) and/or a similar elastic modulusexpansion as the underlying material. The term “body” used herein refersto the main section of an article. The article may be a chambercomponent of a processing chamber. For example, the article may be aheater assembly and the body may be or include one or more heatingelements of the heater assembly. In another example, the article may bea susceptor assembly, and the body may be or include a main section ofthe susceptor assembly. The rare earth metal containing silicate coatingmay be formed using a non-line of sight technique such as atomic layerdeposition (ALD), chemical vapor deposition (CVD), or plasma enhancedCVD (PECVD). The rare earth metal containing silicate coating may alsobe formed by a line-of-sight deposition technique such as physical vapordeposition (PVD) and plasma enhanced PVD (PEPVD). The rare earth metalcontaining silicate coating may also be formed by the combination of anon-line of sight technique (such as ALD, CVD, PECVD) to create aconformal coating covering the whole surface of the article to protectthe surface against reactions with the corrosive process gases, and thena line-of-site deposition technique (such as PVD, PEPVD) to create athick layer or coating over the non-line of sight coating that is directcontact with the process gases and also the process plasma. In someembodiments, the rare earth metal containing silicate coating may alsobe formed by the combination of a line-of-sight deposition technique(such as PVD, PEPVD) to create a thick coating over the surface of thearticle and a non-line of sight technique (such as ALD, CVD, PECVD) tocreate a conformal coating over the line-of-sight thick coating toprotect the underlying materials from the corrosive process gases.

According to embodiments described herein, coatings are formed of rareearth metal containing silicates. To provide good thermal conductivity,thermal expansion adaptability, enough mechanical strength, and a stablestructure that endures thermal fatigue impacts and thermal oxidation athigh-temperatures (e.g., about 400° C. or higher), susceptors forprocess chambers typically include bodies or components formed of agraphite matrix the outside surface of which is coated with a highdensity SiC coating, a TaC coating or a combined SiC/TaC coating.Heaters for process chamber typically have bodies or components formedof ceramic materials such as AlN. Susceptors and heaters are subject tobuildup of materials on their surfaces resulting from exposure toprocess gases within the processing chamber. To remove such buildup,in-situ cleaning of the chambers is performed periodically usingcorrosive plasma chemistries (e.g., fluorine-containing plasmas).However, SiC, TaC, SiC/TaC and AlN are subject to erosion. Accordingly,the coatings described herein are deposited on the surface of thesusceptors and/or heaters to protect the underlying materials of theheaters and/or susceptors against corrosion and delamination.

Rare earth metal containing silicate coatings as described hereinprovide good adhesion to susceptor and heater (e.g., SiC, TaC, SiC/TaCand AlN) materials and do not delaminate or corrode in the presence ofcorrosive plasmas at high temperatures. Such coatings also have acoefficient of thermal expansion (CTE) and/or an elastic modulus that issimilar to materials of the susceptor and heater materials to ensuregood adhesion. Additionally, the rare earth metal containing silicatecoatings as described herein do not affect the thermal properties of thesusceptors and heaters and provide thermal oxidation resistance.

The rare earth metal containing silicate coating includes a rare earthmetal (e.g., yttrium, erbium, lanthanum, lutetium, scandium, gadolinium,samarium, dysprosium, etc. also including herein tantalum, iridium andrhodium) and a silicon containing material (e.g., silicon oxide(Si_(x)O_(y)), silicon carbide (SiC), silicon (Si), silicon carbon oxide(Si_(x)C_(y)O_(z)), silicon nitride (Si₃N₄), silicon carbon nitride(Si_(x)C_(y)N_(z)), silicon oxygen nitride (Si_(x)O_(y)N_(z)), etc.). Aswill be described in more detail below, the coating may be formed bydirectly depositing a rare earth metal (RE) containing silicate material(e.g., RE_(z),Si_(x)O_(y)) or by alternately depositing a rare earthmetal containing layer (e.g., RE_(x)O_(y)) and a Si_(x)O_(y) layer andthen annealing these layers to form the rare earth metal containingsilicate coating. In embodiments, a buffer layer (e.g., of SiO₂, Si,SiC, Si_(x)C_(y)O_(z), Si_(x)O_(y)N_(z), Si_(x)C_(y)N_(z), Si₃N₄, orother Si containing material) may be deposited prior to deposition ofthe rare earth metal containing silicate coating. In embodiments, therare earth metal containing silicate coating may be a multi-layercoating. In embodiments where the rare earth metal containing silicatecoating is deposited on an AlN heater, a buffer layer containing one ormore of Si_(x)O_(y)N_(z), Si_(x)O_(y)N_(z), and Si₃N₄may be deposited onthe surface of the article. In embodiments where the rare earth metalcontaining silicate coating is deposited on a SiC susceptor, a bufferlayer containing one or more of Si_(x)C_(y)O_(z) is included. Inembodiments, a rare earth oxide coating may be deposited over the rareearth silicate coating.

In embodiments, the thickness of the rare earth metal containingsilicate coating may be about 3 nm to about 250 μm, or about 10 nm toabout 100 μm, or about 15 nm to about 50 μm, or about 25 nm to about 50μm, or about 50 nm to about 10 μm, or about 50 nm to about 5 μm, orabout 50 nm to about 1 μm, or about 50 nm to about 500 μm, or about 75nm to about 200 nm. In some embodiments, the thickness of the rare earthmetal containing silicate coating may be about 50 nm, or about 100 nm,or about 500 nm, or about 5 μm, or about 20 μm. The rare earth metalcontaining silicate coating may conformally cover a surface of thesusceptor or heater with a substantially uniform thickness.

The coefficient of thermal expansion (CTE) for SiC is 4.3-5.4×10⁻⁶/K (at300−1273 K), the CTE for TaC is 6.3×10⁻⁶/K, and the CTE for AlN is4.5×10⁻⁶/K. In certain embodiments, the CTE of the rare earth metalcontaining silicate coating is about 4.0 × 10⁻⁶/K (at 300-1273 K) toabout 6.5×10⁻⁶/K (at 300-1273 K), or about 4.3×10⁻⁶/K (at 300-1273 K) toabout 6.3×10⁻⁶/K (at 300-1273 K), or about 4.5×10⁻⁶/K (at 300-1273 K) toabout 6.0×10⁻⁶/K (at 300-1273 K). In embodiments, the rare earth metalcontaining silicate coating has a CTE that is within about ±10% of theCTE of the susceptor material or the heater material.

The elastic modulus for SiC is 410 GPa, the elastic modulus for TaC is330 GPa to 450 GPa and the elastic modulus for AlN is 330 GPa. Incertain embodiments, the elastic modulus of the rare earth metalcontaining silicate coating is about 100 GPa to about 400 GPa, or about110 GPa to about 300 GPa, or about 120 GPa to about 160 GPa, or about124 GPa to about 155 GPa. In embodiments, the rare earth metalcontaining silicate coating has an elastic modulus that is within about±10% of the elastic modulus of the susceptor material or the heatermaterial.

According to embodiments, the rare earth metal containing silicatecoating may be or include at least one material selected from yttriummonosilicate (Y₂SiO₅), yttrium disilicate (Y₂Si₂O₇), erbium monosilicate(Er₂SiO₅), erbium disilicate (Er₂Si₂O₇), tantalum monosilicate(Ta₂SiO₅), tantalum disilicate (Ta₂Si₂O₇), iridium monosilicate(Ir₂SiO₅), iridium disilicate (Ir₂Si₂O₇), rhodium monosilicate(Rh₂SiO₅), rhodium disilicate (Rh₂Si₂O₇), lanthanum monosilicate(La₂SiO₅), lanthanum disilicate (La₂Si₂O₇), lutetium monosilicate(Lu₂SiO₅), lutetium disilicate (Lu₂Si₂O₇), scandium monosilicate(Sc₂SiO₅), scandium disilicate (Sc₂Si₂O₇), gadolinium monosilicate(Gd₂SiO₅), gadolinium disilicate (Gd₂Si₂O₇), samarium monosilicate(Sm₂SiO₅), samarium disilicate (Sm₂Si₂O₇), dysprosium monosilicate(Dy₂SiO₅), dysprosium disilicate (Dy₂Si₂O₇) and combinations thereof. Incertain embodiments, the rare earth metal containing silicate coatingincludes a mixture of a rare earth metal monosilicate and a rare earthmetal disilicate at a volume ratio (monosilicate:disilicate) of about1:20 to about 20:1, or about 1:15 to about 15:1, or about 1:12 to about12:1, or about 1:10 to about 10:1, or about 1:8 to about 8:1, or about1:5 to about 5:1.

In certain embodiments, the rare earth metal containing silicate coatingincludes at least one of Y₂SiO₅ and Y₂Si₂O₇ and is resistant to thermaloxidation at temperatures of about 400° C. or higher, or about 700° C.or higher, or about 1,000° C. or higher, or about 1,200° C. or higher.In embodiments, the rare earth metal containing silicate coatingincludes at least one of Y₂SiO₅ and Y₂Si₂O₇ and is resistant to thermaloxidation at temperatures of about 400° C. to about 1,500° C., or about500° C. to about 1,200° C. or higher, or about 700° C. to about 1,000°C.

In certain embodiments, the rare earth metal containing silicate coatingmay be deposited over a buffer layer/coating on the surface of thearticle (e.g., a susceptor or heater) material. For example, the bufferlayer may be coated onto a SiC, TaC, SiC/TaC or AlN material of thearticle. The buffer layer may be formed of SiO₂, Si, SiC,Si_(x)C_(y)O_(z), Si_(x)O_(y)N_(z), Si_(x)C_(y)N_(z), Si₃N₄ or othersilicon-containing material with or without an amorphous structure. Thebuffer layer may enhance adhesion of the rare earth metal containingsilicate coating to the susceptor or heater material without the need toreduce the thickness of the coating.

In one embodiment, the rare earth metal containing silicate coating is amulti-layer coating that includes a rare earth disilicate layer (e.g.,Y₂Si₂O₇), which coated with a rare earth monosilicate (e.g., Y₂SiO₅)layer. Such multi-layer coating reduces the residual stress induced bythe coating formation and enhances the stability of the coating formedon the susceptor or heater surface. In some embodiments, the multi-layercoating may include a buffer layer as described above and a rare earthmonosilicate (e.g., Y₂SiO₅) layer as a top layer. Without being bound byany particular theory, it is believed that rare earth monosilicates maybe less susceptible to plasma corrosion than rare earth disilicates.

The CTE of yttrium oxide (Y₂O₃) is 9.5×10⁻⁶/K and the elastic modulus ofY₂O₃ is 150 GPa to 180 GPa. At high temperatures, a Y₂O₃ plasmaresistant coating on a susceptor or heater material as described hereinmay not provide sufficient thermal expansion and adhesion properties.Other rare earth metal containing oxide (RE_(x)O_(y)) plasma resistantcoatings similarly may not provide sufficient thermal expansion andadhesion properties at high temperatures. According to certainembodiments, the rare earth metal containing silicate coatings asdescribed herein do not include RE_(x)O_(y) (e.g., Y₂O₃) or more than atrace amount of rare earth metal containing oxide in direct contact withthe susceptor or heater material. In other embodiments, the rare earthmetal containing silicate coating is a multilayer coating where thebuffer layer does not contain yttrium oxide (Y₂O₃), erbium oxide(Er₂O₃), lanthanum oxide (La₂O₃), lutetium oxide (Lu₂O₃), scandium oxide(Sc₂O₃), gadolinium oxide (Gd₂O₃), samarium oxide (Sm₂O₃) dysprosiumoxide (Dy₂O₃), tantalum oxide (Ta₂O₅), iridium oxide (Ir₂O₃) or rhodiumoxide (Rh₂O₃) although a top layer may contain one or more of theseoxides. For example, in certain embodiments the top layer may include arare earth metal containing oxide selected from Y₂O₃, Er₂O₃, Ta₂O₅,Ir₂O₃, Rh₂O₃, La₂O₃, Lu₂O₃, Sc₂O₃, Gd₂O₃, Sm₂O₃, Dy₂O₃, a Y₂O₃ and ZrO₂solid solution, a mixture of Y₄Al₂O₉ and a Y₂O₃ and ZrO₂ solid solutionand combinations thereof. In some embodiments, when the top layercomprises Y₂O₃ it may be converted to yttrium (III) fluoride (YF₃)and/or yttrium oxyfluoride (YOF) through a fluorination process. Thefluorination process can be executed through a wet chemical reaction(e.g. with an acid solution of hydrofluoric acid (HF)), high temperatureannealing (i.e., during a reaction with fluorine containing gases), orduring in situ fluorine-containing plasma processes within a processingchamber.

In some embodiments, the rare earth metal containing silicate coating iscovered by a rare earth oxide coating. The rare earth oxide coating mayinclude a same rare earth material that is included in the rare earthmetal containing silicate coating. Alternatively, or additionally, therare earth oxide coating may include one or more different rare earthmetals that are included in the rare earth metal containing silicatecoating. In some embodiments, the rare earth oxide layer may be Y₂O₃,Er₂O₃, Ta₂O₅, Ir₂O₃, Rh₂O₃, La₂O₃, Lu₂O₃, Sc₂O₃, Gd₂O₃, Sm₂O₃ or Dy₂O₃,Y₃Al₅O₁₂ (YAG), Er₃Al₅O₁₂ (EAG), Y₄Al₂O₉ (YAM), YAlO₃ (YAP), Er₄Al₂O₉(EAM), ErAlO₃ (EAP), a solid solution of Y₂O₃—ZrO₂, a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂, and theircombinations.

With reference to the solid-solution of Y₂O₃—ZrO₂, the rare earth oxidecoating may include Y₂O₃ at a concentration of 10-90 molar ratio (mol %)and ZrO₂ at a concentration of 10-90 mol %. In some examples, thesolid-solution of Y₂O₃—ZrO₂ may include 10-20 mol % Y₂O₃ and 80-90 mol %ZrO₂, may include 20-30 mol % Y₂O₃ and 70-80 mol % ZrO₂, may include30-40 mol % Y₂O₃ and 60-70 mol % ZrO₂, may include 40-50 mol % Y₂O₃ and50-60 mol % ZrO₂, may include 60-70 mol % Y₂O₃ and 30-40 mol % ZrO₂, mayinclude 70-80 mol % Y₂O₃ and 20-30 mol % ZrO₂, may include 80-90 mol %Y₂O₃ and 10-20 mol % ZrO₂, and so on.

With reference to the ceramic compound comprising Y₄Al₂O₉ and asolid-solution of Y₂O₃—ZrO₂, in one embodiment the ceramic compoundincludes 62.93 molar ratio (mol %) Y₂O₃, 23.23 mol % ZrO₂ and 13.94 mol% Al₂O₃. In another embodiment, the ceramic compound can include Y₂O₃ ina range of 50-75 mol %, ZrO₂ in a range of 10-30 mol % and Al₂O₃ in arange of 10-30 mol %. In another embodiment, the ceramic compound caninclude Y₂O₃ in a range of 40-100 mol %, ZrO₂ in a range of 0.1-60 mol %and Al₂O₃ in a range of 0.1-10 mol %. In another embodiment, the ceramiccompound can include Y₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of35-50 mol % and Al₂O₃ in a range of 10-20 mol %. In another embodiment,the ceramic compound can include Y₂O₃ in a range of 40-50 mol %, ZrO₂ ina range of 20-40 mol % and Al₂O₃ in a range of 20-40 mol %. In anotherembodiment, the ceramic compound can include Y₂O₃ in a range of 80-90mol %, ZrO₂ in a range of 0.1-20 mol % and Al₂O₃ in a range of 10-20 mol%. In another embodiment, the ceramic compound can include Y₂O₃ in arange of 60-80 mol %, ZrO₂ in a range of 0.1-10 mol % and Al₂O₃ in arange of 20-40 mol %. In another embodiment, the ceramic compound caninclude Y₂O₃ in a range of 40-60 mol %, ZrO₂ in a range of 0.1-20 mol %and Al₂O₃ in a range of 30-40 mol %. In other embodiments, otherdistributions may also be used for the ceramic compound.

In embodiments, the rare earth oxide coating may have a thickness of afew nanometers (e.g., 1-2 nm) to about 250 microns, or about 3 nm toabout 200 microns, or about 3 nm to about 100 microns, or about 3 nm toabout 20 microns. Any of the aforementioned rare earth oxide coatingsmay include trace amounts of other materials such as ZrO₂, Al₂O₃, SiO₂,B₂O₃, Y₂O₃, Er₂O₃, Ta₂O₅, Ir₂O₃, Rh₂O₃, Nd₂O₃, Nb₂O₅, CeO₂, Sm₂O₃,Yb₂O₃, or other oxides.

In some embodiments, a rare earth oxy-fluoride coating covers the rareearth metal containing silicate coating. The rare earth oxy-fluoridecoating may include any of the aforementioned rare earth oxide coatingswith a portion of the oxygen replaced with fluorine. Accordingly, therare earth oxy-fluoride coating may be a Y—O—F coating, a Y—Zr—O—Fcoating, a Er—O—F coating, and so on.

In some embodiments, the rare earth metal containing silicate coating iscovered by any of the aforementioned rare earth oxide coatings, and therare earth oxide coating is covered by a rare earth oxy-fluoride coatingor a rare earth fluoride coating. For example, a surface of any of theaforementioned rare earth oxide coatings may have undergone afluorination process to convert the surface of the rare earth oxidecoating to a rare earth oxy-fluoride coating or a rare earth fluoridecoating. For example, the rare earth oxide coating may be Y₂O₃, and itmay be covered by a coating of Y—O—F or YF₃. The rare earth oxy-fluoridecoating or rare earth fluoride coating may have a thickness of a fewnanometers (e.g., 1-2 nm) to about 20 microns. In some embodiments, therare earth oxy-fluoride coating or the rare earth fluoride coating has athickness of about 1 nm to about 200 nm, or about 1 nm to about 50 nm,or about 1 nm to about 30 nm.

As will be described in more detail with reference to FIGS. 3A-3C, abuffer layer may be deposited on the surface of the article or the bodyof the article and/or the coating may be a multi-layer stack havingalternating layers of a rare earth metal monosilicate and a rare earthmetal disilicate. The rare earth metal of the monosilicate and thedisilicate may be independently selected from yttrium (Y), erbium (Er),tantalum (Ta), iridium (Ir), rhodium (Rh), lanthanum (La), lutetium(Lu), scandium (Sc), gadolinium (Gd), samarium (Sm) and dysprosium (Dy).

In certain embodiments, the rare earth metal containing silicate coatingincludes one or more of a) a solid solution of a rare earth metalmonosilicate and a rare earth metal disilicate, b) a mixed phasematerial of a rare earth metal monosilicate and a rare earth metaldisilicate, c) a rare earth metal disilicate or a rare earth metalmonosilicate, d) yttria, and e) silica. The rare earth metal containingsilicate coating may include about 50 mol % to about 80 mol % Y₂O₃ andabout 50 mol % to about 20 mol % SiO₂. For example, a bufferlayer/coating may be deposited prior to deposition of the rare earthmetal containing silicate coating and/or a rare earth metal containingoxide layer/coating may cover the rare earth metal containing silicatecoating.

In one embodiment, the rare earth metal containing silicate coating mayhave one or more layers having a polycrystalline structure. In otherembodiments, the rare earth metal containing silicate coating may haveone or more layers having an amorphous structure.

In embodiments the rare earth metal containing silicate coating is aconformal coating having an approximately zero porosity (e.g., aporosity of less than 0.1 vol %). The conformal rare earth metalcontaining silicate coating may also conformally cover surface featuresof the underlying article with a substantially uniform thickness. In oneembodiment, the rare earth metal containing silicate coating has aconformal coverage of the underlying surface that is coated (includingcoated surface features) with a uniform thickness having a thicknessvariation of less than about +/−20%, a thickness variation of +/−10%, athickness variation of +/−5%, or a lower thickness variation.

Also described herein are articles having a rare earth metal containingsilicate coating. In embodiments, the article may be a heater having abody formed of an aluminum nitride heater material. In embodiments, thearticle may be a susceptor having a body formed of a graphite orgraphite composite material coated with silicon carbide, tantalumcarbide or a combination thereof. The article may also be any other typeof article for use in a processing chamber, such as an electrostaticchuck, a gas delivery plate, a showerhead, a chamber liner, a door, aring, and so on. The rare earth metal containing silicate coating mayhave a thickness of about 3 nm to about 250 μm and may include amaterial selected from yttrium monosilicate (Y₂SiO₅), yttrium disilicate(Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅), erbium disilicate (Er₂Si₂O₇),tantalum monosilicate (Ta₂SiO₅), tantalum disilicate (Ta₂Si₂O₇), iridiummonosilicate (Ir₂SiO₅), iridium disilicate (Ir₂Si₂O₇), rhodiummonosilicate (Rh₂SiO₅), rhodium disilicate (Rh₂Si₂O₇), lanthanummonosilicate (La₂SiO₅), lanthanum disilicate (La₂Si₂O₇), lutetiummonosilicate (Lu₂SiO₅), lutetium disilicate (Lu₂Si₂O₇), scandiummonosilicate (Sc₂SiO₅), scandium disilicate (Sc₂Si₂O₇), gadoliniummonosilicate (Gd₂SiO₅), gadolinium disilicate (Gd₂Si₂O₇), samariummonosilicate (Sm₂SiO₅), samarium disilicate (Sm₂Si₂O₇), dysprosiummonosilicate (Dy₂SiO₅), dysprosium disilicate (Dy₂Si₂O₇) andcombinations thereof.

In some embodiments, the rare earth metal containing silicate coating onthe article (e.g., the heater or susceptor) may include a buffer layer,a rare earth metal silicate layer containing at least one of amonosilicate or a disilicate selected from yttrium monosilicate(Y₂SiO₅), yttrium disilicate (Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅),erbium disilicate (Er₂Si₂O₇), tantalum monosilicate (Ta₂SiO₅), tantalumdisilicate (Ta₂Si₂O₇), iridium monosilicate (Ir₂SiO₅), iridiumdisilicate (Ir₂Si₂O₇), rhodium monosilicate (Rh₂SiO₅), rhodiumdisilicate (Rh₂Si₂O₇), lanthanum monosilicate (La₂SiO₅), lanthanumdisilicate (La₂Si₂O₇), lutetium monosilicate (Lu₂SiO₅), lutetiumdisilicate (Lu₂Si₂O₇), scandium monosilicate (Sc₂SiO₅), scandiumdisilicate (Sc₂Si₂O₇), gadolinium monosilicate (Gd₂SiO₅), gadoliniumdisilicate (Gd₂Si₂O₇), samarium monosilicate (Sm₂SiO₅), samariumdisilicate (Sm₂Si₂O₇), dysprosium monosilicate (Dy₂SiO₅), dysprosiumdisilicate (Dy₂Si₂O₇) and combinations thereof, and a rare earth metalcontaining oxide layer covering the rare earth metal silicate layer, therare earth metal oxide selected from yttrium oxide (Y₂O₃), erbium oxide(Er₂O₃), tantalum oxide (Ta₂O₅), iridium oxide (Ir₂O₃), rhodium (Rh₂O₃),lanthanum oxide (La₂O₃), lutetium oxide (Lu₂O₃), scandium oxide (Sc₂O₃),gadolinium oxide (Gd₂O₃), samarium oxide (Sm₂O₃) dysprosium oxide(Dy₂O₃) and combinations thereof.

In some embodiments the article (e.g., a susceptor or heater) or thebody of the article may include at least one gas hole, wherein the gashole has an aspect ratio of length to diameter (L:D) of about 5:1 toabout 100:1, or about 7:1 to about 50:1, or about 10:1 to about 25:1.The rare earth metal containing silicate coating may conformally coverthe body of the article and a surface of the gas hole. In someembodiments, the article or the body of the article may include afeature having an aspect ratio of depth to width (D:W) of about 5:1 toabout 100:1, or about 7:1 to about 50:1, or about 10:1 to about 20:1.The rare earth metal containing silicate coating may conformally coverthe body of the article and a surface of the feature.

In some embodiments, the article (e.g., a susceptor) includes a bodyhaving silicon carbide on a surface thereof, and the rare earth metalcontaining silicate coating contains at least about 50 vol % to about 80vol % of a yttrium silicate and up to about 20 vol %, or up to about 30vol %, or up to about 40 vol %, or up to about 50 vol %, or about 20 vol% to about 50 vol % of other phases (e.g., Y₂O₃, SiO₂, etc.). In someembodiments, the article (e.g., a susceptor) includes a body havingtantalum carbide on a surface thereof, and the rare earth metalcontaining silicate coating contains at least about 50 mol %, or atleast about 60 mol %, or at least about 70 mol %, or at least about 80mol %, or about 50 vol % to about 80 vol % of a rare earth metalcontaining silicate and up to about 20 vol %, or up to about 30 vol %,or up to about 40 vol %, or up to about 50 vol %, or about 20 vol % toabout 50 vol % of other phases (e.g., RE_(x)O_(y), SiO2, etc.). In yetfurther embodiments, the article (e.g., a heater) includes a body formedof aluminum nitride and the rare earth metal containing silicate coatingcontains about 50 vol % to about 80 vol % of rare earth metal containingsilicate(s) and about 20 vol % to about 50 vol % of other phases (e.g.,RE_(x)O_(y), SiO₂, etc.).

Embodiments are discussed herein with regards to rare earth metalcontaining silicate coatings on heaters and susceptors. However,embodiments discussed with regards to heaters and susceptors also applyto other chamber components of processing chambers such as electrostaticchucks (ESCs), gas delivery plates, showerheads, lids, nozzles, chamberliners, rings, view ports, and so on.

FIG. 1 is a sectional view of a semiconductor processing chamber 100having one or more chamber components that are coated with a rare earthmetal containing silicate coating in accordance with embodimentsdescribed herein. The base materials of at least some components of thechamber may include one or more of aluminum (Al), titanium (Ti) andstainless steel (SST). The processing chamber 100 may be used forprocesses in which a corrosive plasma environment having plasmaprocessing conditions is provided. For example, the processing chamber100 may be a chamber for a plasma etcher or plasma etch reactor, aplasma cleaner, CVD, a metalorganic chemical vapor deposition (MOCVD)chamber, plasma enhanced CVD, PVD or ALD reactors and so forth. Anexample of an article that may include a rare earth metal containingsilicate coating is a susceptor or a heater.

In one embodiment, the processing chamber 100 includes a chamber body102 and a showerhead 130 that encloses an interior volume 106. Theshowerhead 130 may include a showerhead base and a showerhead gasdistribution plate. Alternatively, the showerhead 130 may be replaced bya lid and a nozzle in some embodiments, or by multiple pie shapedshowerhead compartments and plasma generation units in otherembodiments. The chamber body 102 may be fabricated from aluminum,stainless steel or other suitable material such as titanium (Ti). Thechamber body 102 generally includes sidewalls 108 and a bottom 110. Anouter liner 116 may be disposed adjacent the sidewalls 108 to protectthe chamber body 102.

An exhaust port 126 may be defined in the chamber body 102, and maycouple the interior volume 106 to a pump system 128. The pump system 128may include one or more pumps and throttle valves utilized to evacuateand regulate the pressure of the interior volume 106 of the processingchamber 100.

The showerhead 130 may be supported on the sidewall 108 of the chamberbody 102. The showerhead 130 (or lid) may be opened to allow access tothe interior volume 106 of the processing chamber 100, and may provide aseal for the processing chamber 100 while closed. A gas panel 158 may becoupled to the processing chamber 100 to provide process and/or cleaninggases to the interior volume 106 through the showerhead 130 or lid andnozzle. Showerhead 130 may be used for processing chambers used fordielectric etch (etching of dielectric materials). The showerhead 130may include a gas distribution plate (GDP) and may have multiple gasdelivery holes 132 throughout the GDP. The showerhead 130 may includethe GDP bonded to an aluminum base or an anodized aluminum base. The GDPmay be made from Si or SiC, or may be a ceramic such as Y₂O₃, Al₂O₃,Y₃Al₅O₁₂ (YAG), and so forth.

For processing chambers used for conductor etch (etching of conductivematerials), a lid may be used rather than a showerhead. The lid mayinclude a center nozzle that fits into a center hole of the lid. The lidmay be a ceramic such as Al₂O₃, Y₂O₃, YAG, or a ceramic compoundcomprising Y₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂. The nozzle mayalso be a ceramic, such as Y₂O₃, YAG, or the ceramic compound comprisingY₄Al₂O₉ and a solid-solution of Y₂O₃—ZrO₂.

Examples of processing gases that may be used to process substrates inthe processing chamber 100 include halogen-containing gases, such asCF₄, C₂F₆, C₄F₈, SF₆, SiCl₄, HBr, NF₃, CF₄, CHF₃, CH₂F₃, F, NF₃, Cl₂,CCl₄, BCl₃ and SiF₄, among others, and other gases such as O₂, H₂, orN₂O. Examples of carrier gases include N₂, He, Ar, and other gases inertto process gases (e.g., non-reactive gases).

A heater assembly 148 is disposed in the interior volume 106 of theprocessing chamber 100 below the showerhead 130 or lid. The heaterassembly 148 includes a support 136 that holds a substrate 144 duringprocessing. The support 136 is attached to the end of a shaft (notshown) that is coupled to the chamber body 102 via a flange 164. Thesupport 136, shaft and flange 164 may be constructed of a heatermaterial containing AlN, for example, an AlN ceramic. The support 136may further include mesas 156 (e.g., dimples or bumps) (not shown). Thesupport 136 may additionally include wires, for example, tungsten wires(not shown), embedded within the heater material of the support 136. Inone embodiment, the support 136 may include metallic heater and sensorlayers that are sandwiched between AlN ceramic layers. Such an assemblymay be sintered in a high-temperature furnace to create a monolithicassembly. The layers may include a combination of heater circuits,sensor elements, ground planes, radio frequency grids and metallic andceramic flow channels. The heater assembly 148 may provide a heatertemperature of up to about 650° C. under vacuum conditions (e.g., about1 mTorr to about 5 Torrs). A rare earth metal containing silicatecoating in accordance with embodiments described herein may be depositedon the support 150 or on all surfaces of the heater assembly 148(including the support 136, shaft and flange 154) within the chamber100.

In alternative embodiments, the heater assembly 148 may be replaced by asusceptor (not shown), which may be coated by a rare earth metalcontaining silicate coating. Additionally, or alternatively, othercomponents of the processing chamber 100 may be coated with the rareearth metal containing silicate coating, such as the showerhead 130,outer liner 116, and so on.

FIG. 2A depicts a heater assembly 200 having coated components and/or acoated body in accordance with embodiments described herein. The heaterassembly 200 includes a support 205 attached to an end of an interiorshaft 215. The interior shaft 215 is situated within the interior volumeof the processing chamber (not shown). The interior shaft is attached toan exterior shaft 220 via a flange 225. The support 205 includes mesas210. All surfaces that may be exposed to corrosive gases and plasmaswithin the processing chamber may be coated with a rare earth metalcontaining silicate coating 240 in accordance with embodiments describedherein.

The rare earth metal containing silicate coating 240 may comprise one ormore earth metal containing silicate material on a surface of thesupport 205 and/or on all surfaces of the heater assembly that may beexposed to corrosive gases or plasma within the processing chamber. Therare earth metal containing silicate coating may be a single-layercoating having little or no impact on the thermal properties of theheater material of the support 205 or on the performance of the heatergenerally. The single-layer rare earth metal containing silicate coatingmay have a thickness of about 3 nm to about 250 μm, or about 10 nm to100 μm, or about 15 nm to 50 μm, or about 25 nm to 50 μm, or about 50 nmto 10 μm, or about 50 nm to 5 μm, or about 50 nm to 10 μm, or about 50nm to about 500 nm, or about 75 nm to about 200 nm. In some embodiments,the thickness of the rare earth metal containing silicate coating may beabout 50 nm, or about 100 nm, or about 500 nm, or about 5 μm, or about20 μm, or about 250 μm. In some embodiments, the thickness of thesingle-layer rare earth metal containing silicate coating may be about50 nm, or about 75 nm, or about 100 nm, or about 125 nm, or about 150nm. The rare earth metal containing silicate coating may alternativelybe a multi-layer coating having two or more layers. For example, a firstlayer may be a rare earth metal containing monosilicate and a secondlayer may be a rare earth metal containing disilicate. In anotherexample, the rare earth metal containing silicate coating may includealternating layers of a rare earth metal containing monosilicate and arare earth metal containing disilicate. The rare earth metal containingsilicate coating may have a total thickness of about 3 nm to about 250μm in embodiments. One or more parts of the heater assembly 200 may alsobe coating with a buffer layer underneath the rare earth metalcontaining silicate layer and/or a rare earth oxide layer over the rareearth metal containing silicate layer. The rare earth metal containingsilicate coating used on the one or more parts of the heater assembly200 may also include any of the other embodiments of a rare earth metalcontaining silicate coating discussed elsewhere herein.

The heater may include one or more body formed from an aluminum nitride(AlN) material or other suitable material having a comparable chemicalresistance and mechanical, thermal and electrical properties. The heatermaterial may have embedded therein, wires (e.g., tungsten wires) tosupply electricity. In embodiments, the heater material may be an AlNceramic, a silicon carbide (SiC) ceramic, an aluminum oxide (Al₂O₃)ceramic or any combination thereof. Different heater materials may havedifferent reaction properties such that one composition may form areactant with a higher vapor pressure than another composition whenexposed to high temperatures, low vacuum pressures and aggressivechemistries. For example, when a typical high temperature heater havingan AlN material ceramic is exposed to nitrogen trifluoride (NF₃) plasmaunder high temperature (e.g., up to about 650° C.) and vacuum conditions(e.g., about 50 mTorr to about 200 mTorr), the reaction producesaluminum trifluoride (AlF₃). The AlF₃ is able to sublime and depositonto components within the chamber. During a subsequent process step,the deposited material may peel or flake or otherwise detach from theother chamber components and deposit as particles onto a wafer thereinresulting in defects. Providing a rare earth metal containing silicatecoating on the heater can provide resistance to thermal oxidation athigh temperatures (e.g., at least about 1,000° C.) and resistance tofluorination. The rare earth metal containing silicate coating can alsobe dense with a porosity of about 0% (e.g., the rare earth metalcontaining silicate coating can be porosity-free in embodiments). Therare earth metal containing silicate coatings also can be resistant tocorrosion and erosion from plasma etch chemistries, such as CCl₄/CHF₃plasma etch chemistries, HCl₃Si etch chemistries and NF₃ etchchemistries.

FIG. 2B depicts a susceptor assembly having one or more body such as asusceptor block (wafer support plate) 265 and a support stand(cylindrical member) 255 with a bottom plate 260. A gas feeding tube 270is connected to the bottom plate 260 of cylindrical member 255. Wiringleads 295, 296 for a heater (not shown), wiring leads 297 for athermocouple (not shown), and a lead 290 to a high-frequency metallicelectrode (not shown) are routed to pass through the bottom plate 265 ofcylindrical member 255. The gas feeding tube 270 is connected to a massflow controller 275 through a flexible tube 285. The mass flowcontroller 275 may be connected to a gas cylinder 280 through a gas pipe(not shown). The susceptor support plate 265 may be formed of, forexample, a graphite or graphite composite material coated with, forexample, SiC, TaC or a combination of SiC/TaC.

Some or all surfaces of the susceptor assembly 250 that may be exposedto corrosive gases and/or plasmas are coated with a rare earth metalcontaining silicate coating in accordance with embodiments describedherein. Additionally, some or all surfaces of the susceptor assembly 250that are exposed to corrosive gases and/or plasmas may also be coatingwith a buffer layer underneath the rare earth metal containing silicatecoating and/or a rare earth oxide layer over the rare earth metalcontaining silicate coating. The susceptor wafer support plate 265 maybe mounted on the top surface of the cylindrical member 255 and attachedwith screws (not shown), which also may be coated with the rare earthmetal containing silicate coating. The flat susceptor wafer supportplate 265 may be mounted to the bottom surface of the cylindrical member255 also with screws (not shown), which can be coated with the rareearth metal containing silicate coating as described herein.

Coatings according to embodiments described herein may be formed using adeposition process selected from chemical vapor deposition (CVD), plasmaenhanced chemical vapor deposition (PECVD), physical vapor deposition(PVD), plasma enhanced physical vapor deposition (PEPVD) and atomiclayer deposition (ALD). CVD is a well-known technique for depositingpure metal coatings. Ina typical CND process, a substrate is exposed toat least one volatile precursor under ultra-high vacuum conditions. Theat least one precursor reacts or decomposes on the substrate surface toform a film. The reaction chamber is subsequently purged with inert gasflowing there-through. In a. PECVD process, chemical reactions areinitiated by the creation of a plasma of the reactive precursor gases.In an ALD process, a thin film layer is grown by repeatedly exposing thesurface of a substrate to pulses of gaseous chemical precursors thatchemically react with the surface one at a time in a self-limitingmanner. CVD and ALD are non-line-of-sight processes that may be used tocoat high aspect ratio features. A PVD process also takes place undervacuum conditions and typically involves sputtering and/or evaporationof a target material to form a gas that deposits and/or reacts on asurface of the substrate. PVD (typically, including evaporation, plasmspray, etc.) is a line-of-sight process. In a PEPVD process (typically,including ion assisted deposition, ion assisted evaporation deposition,ion assisted sputtering deposition, ion plating, etc.), the plasma orenergetic ions are generated to react with deposition materials from thePVD processes, such as the ion beams, and involve sputtering orevaporation of target materials. PEPVD is a line-of-sight process, butcan be modified as a non-line-of-sight process in cases where thesubstrate is biased during the deposition processes. As compared to ALD,PVD and PEPVD can deposit a relatively thick rare earth metal containingsilicate or oxide layer or coating (up to about 500 μm, or up to about250 μm, or from about 5 μm to about 250 μm) at a relatively lowdeposition temperature (<200° C.).

FIG. 3A depicts an embodiment of an atomic layer deposition (ALD)process 300 for growing or depositing a rare earth metal containingsilicate coating on an article (e.g., a heater or susceptor support orentire heater or susceptor assembly). FIG. 3B depicts one embodiment ofan ALD deposition process 301 to grow or deposit a rare earth metalcontaining silicate coating on an article. FIG. 3C depicts anotherembodiment of an ALD deposition process 302 as described herein. FIG. 3Ddepicts an embodiment of a hybrid deposition process 304 as describedherein.

FIGS. 3A-3D illustrate an article 310 having a surface. Article 310 mayrepresent a body of a semiconductor process chamber component, includingbut not limited to, a body of a heater, susceptor and/or all surfaces ofa heater assembly or a susceptor assembly within a processing chamber.The article 310 may be formed of a graphite composite coated with SiC,TaC or a combination of SiC/TaC, a ceramic dielectric material, such asAN, a metal-ceramic composite (e.g., Al₂O₃/SiO₂, Al₂O₃/MgO/SiO₂, SiC,Si₃N₄, AlN/SiO₂ and the like), a metal (such as aluminum, stainlesssteel) or other suitable materials, and may further comprise materialssuch as Al₂O₃, SiO₂, and so on.

For ALD processes, either adsorption of a precursor onto a surface or areaction of a reactant with the adsorbed precursor may be referred to asa “half-reaction.” During a first half reaction, a precursor is pulsedonto a surface of the article 310 for a period of time sufficient toallow the precursor to fully adsorb onto the surface. The adsorption isself-limiting as the precursor will adsorb onto a finite number ofavailable sites on the surface, forming a uniform continuous adsorptionlayer on the surface. Any sites that have already adsorbed with aprecursor will become unavailable for further adsorption with the sameprecursor unless and/or until the adsorbed sites are subjected to atreatment that will form new available sites on the uniform continuouscoating. Exemplary treatments may be plasma treatment, treatment byexposing the uniform continuous adsorption layer to radicals, orintroduction of a different precursor able to react with the most recentuniform continuous layer adsorbed to the surface.

A typical reaction cycle of an ALD process starts with a precursor(i.e., a chemical A) flooded into an ALD chamber and adsorbed ontosurfaces of the article (including surfaces of holes and features withinthe articles). The excess precursor may then be flushed out of the ALDchamber before a reactant (i.e., a chemical R) is introduced into theALD chamber and subsequently flushed out. For ALD, the final thicknessof material is dependent on the number of reaction cycles that are run,because each reaction cycle will grow a layer of a certain thicknessthat may be one atomic layer or a fraction of an atomic layer.

Aside from being a conformal process, ALD is also a uniform process andis capable of forming very thin films, for example, having a thicknessof about 3 nm or more. All exposed surfaces of the article will have thesame or approximately the same amount of material deposited. The ALDtechnique can deposit a thin layer of material at a relatively lowtemperature (e.g., about 25° C. to about 350° C.) so that it does notdamage or deform any materials of the component. Additionally, the ALDtechnique, can also deposit a layer of material within complex features(e.g., high aspect ratio features) of the component. Furthermore, theALD technique generally produces relatively thin (i.e., 20 μm or less)coatings that are porosity-free (i.e., pin-hole free), which mayeliminate crack formation during deposition.

The rare earth metal containing silicate coating may be grown ordeposited using ALD with a rare earth metal-containing precursor, asilicon containing precursor and a reactant containing oxygen, forexample, oxygen gas (O₂), water vapor (H₂O), ozone (O₃), oxygen radicals(O*) or other oxygen-containing material. The rare earthmetal-containing precursor may contain yttrium, erbium, tantalum,iridium, rhodium, lanthanum, lutetium, scandium, gadolinium, samarium,dysprosium, etc. The silicon containing precursor may be, for example,silane, tris(tert-butoxy)silanol, etc. In some embodiments, a mixture oftwo precursors is introduced together, where the mixture includes afirst percentage of a silicon precursor and a second percentage of arare earth metal-containing precursor. The mixture may include a ratioof yttrium precursor to silicon precursor that is suitable to form atarget type of silicate. For example, if the target silicate is Y₂SiO₅,then there may be an approximately 2:1 ratio of the yttrium precursor tosilicon precursor. If the target silicate is Y₂Si₂O₇, then there may bean approximately 1:1 ratio of the yttrium precursor to siliconprecursor. In some embodiments, the rare earth metal containingprecursor is a yttrium containing precursor, for example,tris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide,tris(cyclopentadienyl)yttrium(III), or Y(thd)3(thd=2,2,6,6-tetramethyl-3,5-heptanedionato). In an alternativeembodiment, rather than a mixture of a separate silicon precursor andrare earth precursor, a single precursor for a rare earth silicate maybe used.

Referring to FIG. 3A, article 310 may be introduced to a mixture of afirst precursor 360 of a rare earth material and a second precursor 362of silicon for a first duration until a surface of article 310 is fullyadsorbed with the first precursor 360 and the second precursor 362 toform an adsorption layer 314. The first precursor 360 may be a rareearth precursor (e.g., a yttrium precursor, an erbium precursor, and soon). The second precursor 362 may be a silicon precursor such as silane,dichlorosilane, 2,4,6,8-tetramethylcyclotetrasiloxane,dimethoxydimethylsilane, disilane, methylsilane,octamethylcyclotetrasiloxane, tris(isopropoxy)silanol,tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol and so on.Alternatively, a single precursor for a rare earth silicate may be used.Subsequently, article 310 may be introduced to a first reactant 365 toreact with the adsorption layer 314 to grow a solid layer 316 (e.g., sothat the layer 316 is fully grown or deposited, where the terms “grown”and “deposited” may be used interchangeably herein). For a single layerrare earth metal containing silicate coating, the first precursor 360may be a precursor for a rare earth metal-containing material such as arare earth monosilicate and/or a rare earth disilicate. The firstreactant 365 may be oxygen, water vapor, ozone, oxygen radicals, orother oxygen source. ALD is thus used to form the layer 316. Layer 316may be a single-layer rare earth metal containing silicate coating, forexample, a rare earth monosilicate (e.g., Y₂SiO₅) or a rare earthdisilicate (e.g., Y₂Si₂O₇). Whether the layer 316 is a monosilicate, adisilicate, or mixture thereof may depend on a ratio of the yttriumprecursor to the silicon precursor.

The rare earth metal containing silicate coating (e.g., Layer 316 or theresulting coating after deposition) is uniform, continuous andconformal. The coating is porosity free (e.g., have a porosity of zero)or have an approximately zero porosity in embodiments (e.g., a porosityof 0% to 0.01%). Layer 316 may have a thickness of less than one atomiclayer to a few atoms in some embodiments after a single ALD depositioncycle. Some metalorganic precursor molecules are large. After reactingwith the reactant 365, large organic ligands may be gone, leaving muchsmaller metal atoms. One full ALD cycle (e.g., that includesintroduction of precursors 360 followed by introduction of reactants365) may result in the formation of a layer with an average thicknessless than a single unit cell.

Multiple full ALD deposition cycles may be implemented to deposit athicker layer 316, with each full cycle (e.g., including introducingprecursor 360, flushing, introducing reactant 365, and again flushing)adding to the thickness by an additional fraction of an atom to a fewatoms. As shown, up to n full cycles may be performed to grow the layer316, where n is an integer value greater than 1. In some embodiments, arare earth metal disilicate layer can be grown on article 310 as layer316 via a full cycle or sequence of cycles, and then, after purging thedeposition chamber, another full deposition cycle or sequence ofdeposition cycles can be used to grow a rare earth metal monosilicatelayer on top of the rare earth disilicate layer. Alternatively, layer316 can be a rare earth monosilicate layer and a rare earth disilicatelayer can be grown on top of the rare earth monosilicate layer.

In some embodiments, a similar ALD process to that described withreference to FIG. 3A may be performed to deposit a buffer layer prior todeposition of a rare earth metal containing silicate coating. The bufferlayer may by SiO₂, Si, SiC, Si_(x)C_(y)O_(z), Si_(x)O_(y)N_(z),Si_(x)C_(y)N_(z), Si₃N₄ or other Si containing material. For example, asilicon precursor may be used to deposit Si followed by an oxygen sourcereactant to form an SiO₂ buffer layer.

In some embodiments, a similar ALD process to that described withreference to FIG. 3A may be performed to deposit a rare earth oxidelayer over the rare earth metal containing silicate coating. Forexample, a yttrium precursor may be used to deposit yttrium followed byan oxygen source reactant to form a Y₂O₃ coating over the rare earthmetal containing silicate coating. The rare earth metal containingsilicate coating with a top rare earth oxide layer provides robustplasma resistance and mechanical properties without significantlyimpacting the thermal and electrical properties of the article (e.g.,susceptor or heater). The coating may protect the article from erosion,provide resistance to oxidation and may maintain adhesion even at hightemperatures.

FIG. 3B describes a deposition process 301 that includes deposition ofan optional buffer layer 310 followed by deposition of layer 316 asdescribed with reference to FIG. 3A. The buffer layer 310 may have thesame or a similar material to the underlying material of the article.For example, the buffer layer may be formed of a Si_(x)O_(y) material(e.g., SiO₂) or other silicon-containing material with or without anamorphous structure.

Referring to FIG. 3B, article 310 may be introduced to a first precursor350 for a first duration until a surface of article 310 is fullyadsorbed with the first precursor 350 to form an adsorption layer 305.Subsequently, article 310 may be introduced to a first reactant 355 toreact with the adsorption layer 305 to grow a solid layer 311. The firstprecursor 350 may be a silicon containing precursor such as silane,dichlorosilane, 2,4,6,8-tetramethylcyclotetrasiloxane,dimethoxydimethylsilane, disilane, methylsilane,octamethylcyclotetrasiloxane, tris(isopropoxy)silanol,tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol . The first reactant355 may be oxygen, water vapor, ozone, oxygen radicals, or other oxygensource. Layer 311 thus, forms a buffer layer between the article and therare earth metal containing silicate coating. Layer 316 may then begrown on the buffer layer 311 by repeating the process and as describedwith respect to FIG. 3A.

The thickness of the buffer layer 311 may be about 1 nm to about 50 nm,or about 2 nm to about 25 nm, or about 5 nm to about 10 nm. In certainembodiments, the thickness of the buffer layer is about 1 nm, or about 5nm, or about 10 nm, or about 15 nm. The thickness of the rare earthmetal-containing layer prepared by ALD may be about 3 nm to about 20 μm,or about 25 nm to about 5 μm, or about 50 nm to about 500 nm, or about75 nm to about 200 nm. In some embodiments, the thickness of thesingle-layer rare earth metal containing silicate coating may be about50 nm, or about 75 nm, or about 100 nm, or about 125 nm, or about 150nm, or about 200 nm, or about 300 nm. In certain embodiments, the totalthickness of the rare earth metal containing silicate coating includingthe buffer layer and the rare earth metal-containing layer may be about50 nm, or about 100 nm, or about 500 nm, or about 5 μm, or about 20 μm.

With reference to FIG. 3C, in some embodiments, a multi-layer stack maybe deposited on the article 310 using ALD. Article 310 having optionalbuffer layer 311 may be inserted into a deposition chamber. Optionalbuffer layer 311 may be formed as set forth with reference to FIG. 3A orFIG. 3B. To form the multi-layer stack, article 310 may be introduced toone or more precursors 380 containing one or more rare earthmetal-containing materials for a duration until layer 311 is fullyadsorbed with the one or more precursors 380 to form layer 322.Subsequently, article 310 may be introduced to a reactant 382 to reactwith layer 322 to grow layer 324. Accordingly, a rare earth metalcontaining oxide layer 324 may be fully grown or deposited over layer311 using ALD. In an example, precursor 380 may be a yttrium containingprecursor used in the first half cycle, and reactant 382 may be H₂O usedin the second half cycle. The rare earth metal-containing layer 324 maybe, for example, Y₂O₃ or Er₂O₃. The deposition cycle including theintroduction of the precursors 380 followed by the introduction of thereactant 382 may be performed up to x times, where x is an integer witha value of 1-10 in embodiments.

Article 310 having layer 311 and layer 324 may be introduced to one ormore precursors 384 for a duration until layer 324 is fully adsorbedwith the one or more precursors 384 to form layer 326. Subsequently,article 310 may be introduced to a reactant 386 to react with layer 326to grow an additional layer 328. Accordingly, the additional layer 328is fully grown or deposited over layer 324 using ALD. In an example,precursor 384 may be a silicon precursor such as silane ortris(tert-butoxy)silanol used in the first half cycle, and reactant 386may be H₂O or another oxygen source used in the second half cycle. Thelayer 328 may be a silicon dioxide or other SiO_(x) layer inembodiments.

The deposition cycle including the introduction of the precursors 384followed by the introduction of the reactant 386 may be performed up toy times, where y is an integer with a value of 1-10 in embodiments. Asshown, the deposition of layer 324 and layer 328 may be repeated n timesto form a stack 337 of alternating layers, where n is an integer valueof 1 or more (e.g., greater than 2 in some embodiments). N may representa finite number of layers selected based on the targeted thickness andproperties. The stack 337 of alternating layers may be considered as arare-earth metal-containing layer containing multiple alternatingsub-layers. Accordingly, precursors 380, reactants 382, precursors 384and reactants 386 may be repeatedly introduced sequentially to grow ordeposit additional alternating layers 330, 332, 334, 336, and so on.Each of the layers 324, 328, 330, 332, 334, 336, and so on may be verythin layers having an average thickness of less than a single atomiclayer to a few atomic layers. Alternatively, one or more of the layers324, 328, 330, 332, 334, 336 may have a thickness of up to 1-2 nm insome embodiments. In a further embodiment, one or more of the layers324, 328, 330, 332, 334, 336 may have a thickness of up to about 5 μm.

The alternating layers 324-336 described above may have a 1:1 ratio,wherein for each layer of one material there is one layer of anothermaterial. However, in other embodiments there may be other ratios suchas 2:1, 3:1, 3:2, 4:1, 1:4, 2:3, 1:3, 1:2, and so on between thedifferent types of layers. For example, two Y₂O₃ layers may be depositedfor every SiO₂ layer in an embodiment. Additionally, the stack 337 ofalternating layers 324-336 has been described as an alternating seriesof two types of metal layers. However, in other embodiments more thantwo types of metal layers may be deposited in an alternating stack 337.For example, the stack 337 may include three different alternatinglayers (e.g., a first layer of Y₂O₃, a first layer of SiO₂, a firstlayer of ZrO₂, a second layer of Y₂O₃, a second layer of SiO₂, a secondlayer of ZrO₂, and so on).

After the stack 337 of alternating layers has been formed, an annealprocess may be performed to cause the alternating layers of differentmaterials to diffuse into one another and form a complex silicate havinga single phase or multiple phases. After the annealing process, thestack of alternating layers 337 may therefore become a single rare-earthmetal-containing silicate layer 338. For example, if the layers in thestack are Y₂O₃ and SiO₂, then the resulting rare-earth metal-containingoxide layer 338 may consist of a Y₂SiO₅ phase and/or a Y₂Si₂O₇ phase.

The ratio of the thickness of the layers 324 to the thickness of thelayers 328 (and ratio of the number of times x that deposition cyclesare performed to the number of times y that deposition cycles areperformed) may control a composition of the rare earth metal containingsilicate coating in embodiments. For example, a thickness ratio of 2:1of Y₂O₃ layers to SiO₂ layers may result in a Y₂SiO₅ phase, while athickness ratio of 1:1 of Y₂O₃ layers to SiO₂ layers may result in aY₂Si₂O₇ phase.

Each layer of the rare earth metal-containing material may have athickness of about 5-10 angstroms and may be formed by performing about1 to about 10 cycles of an ALD process, where each cycle forms ananolayer (or slightly less or more than a nanolayer) of the rare earthmetal-containing material. In one embodiment, each layer of the rareearth metal containing silicate coating is formed using about 6 to about8 ALD cycles. Each SiO₂ layer may be formed from about 1 to about 2 ALDcycles (or a few ALD cycles) and may have a thickness of less than anatom to a few atoms. The stack 337 of alternating layers may have atotal thickness of about 3 nm to about 20 μm.

In some of the embodiments described with reference to FIGS. 3A-3C, thesurface reactions (e.g., half-reactions) are done sequentially, and thevarious precursors and reactants are not in contact in embodiments.Prior to introduction of a new precursor or reactant, the chamber inwhich the ALD process takes place may be purged with an inert carriergas (such as nitrogen or air) to remove any unreacted precursor and/orsurface-precursor reaction byproducts. In some embodiments, at least twoprecursors are used concurrently (e.g., as described with reference toFIG. 3A), in other embodiments at least three precursors are used and inyet further embodiments at least four precursors are used.

ALD processes may be conducted at various temperatures depending on thetype of process. The optimal temperature range for a particular ALDprocess is referred to as the “ALD temperature window.” Temperaturesbelow the ALD temperature window may result in poor growth rates andnon-ALD type deposition. Temperatures above the ALD temperature windowmay result in reactions taken place via a chemical vapor deposition(CVD) mechanism. The ALD temperature window may range from about 100° C.to about 650° C. In some embodiments, the ALD temperature window is fromabout 20° C. to about 300° C., or about 25° C. to about 250° C., orabout 100° C. to about 200° C., or about 50° C. to 150° C. , or about20° C. to 125° C.

The ALD process allows for a conformal rare earth metal containingsilicate coating having uniform thickness on articles and surfaceshaving complex geometric shapes, holes with high aspect ratios (e.g.,pores), and three-dimensional structures. Sufficient exposure time ofeach precursor to the surface enables the precursor to disperse andfully react with the surfaces in their entirety, including all of itsthree-dimensional complex features. The exposure time utilized to obtainconformal ALD in high aspect ratio structures is proportionate to thesquare of the aspect ratio and can be predicted using modelingtechniques. Additionally, the ALD technique is advantageous over othercommonly used coating techniques because it allows in-situ on demandmaterial synthesis of a particular composition or formulation without alengthy and difficult fabrication of source materials (such as powderfeedstock and sintered targets).

Any of the ALD processes 300, 301, 302 may be performed multiple timesto form a multi-layer rare earth metal containing silicate coatingcomprising at least a first layer and a second layer. The first layermay be a first type of rare earth silicate and the second layer may be asecond type of rare earth silicate. For example, the first layer may bea rare earth disilicate and the second layer may be a rare earthmonosilicate. In another example, the first layer may include a firstratio of a rare earth monosilicate and a rare earth disilicate and thesecond layer may include a second ratio of the rare earth monosilicateand the rare earth disilicate. For example, the first layer may includea rare earth metal monosilicate and a rare earth metal disilicate at afirst volume ratio (monosilicate:disilicate) of about 1:20 to about20:1, and the second layer may include the rare earth metal monosilicateand the rare earth metal disilicate at a volume ratio(monosilicate:disilicate) of about 1:10 to about 10:1.

According to embodiments herein, as shown in FIG. 3D, a hybrid formationof the rare earth metal containing silicate coating on the article by atleast one non-line-of-sight deposition approach and at least oneline-of-sight deposition approach may be employed. Such rare earth metalcontaining silicate coatings formed by this hybrid process can deposit athick coating on the article or a body of the article, which can providea long service life of the article or a body of the article.

A non-line-of-sight deposition approach, such as ALD, can deposit aconformal coating over the entire surface of the article (e.g.,including high aspect ratio features such as holes and gas lines), butthe thickness of such coatings are usually limited to less than about 25μm. A line-of-sight deposition approach, such as PVD and PEPVD, candeposit relatively thick coatings, for example, up to about 500 μm, orup to about 250 μm, or from about 5 μm to about 250 μm, or from about 5μm to about 500 μm, or even greater than about 500 μm, but such coatingswould not conformally cover the surface of the article or a body of thearticle (e.g., would not be able to reach the surface of high aspectratio features such as holes and gas lines).

The combination of a non-line-of-sight deposition approach with aline-of-sight deposition approach can provide conformal coverage of thearticle's entire surface, thereby protecting the article from corrosionin the working environment (e.g., by corrosive gas, thermal oxidation,etc.), and a thick plasma resistant coating to further protect thearticle and its surfaces from aggressive process gases or plasmaerosion, such as in plasma etch chambers.

FIG. 3D describes the deposition of a conformal rare earth metalcontaining silicate coating on an article using a hybrid process, forexample, involving an ALD process 301 as described with reference toFIG. 3B, and a line-of-sight process 304 such as PVD, PEPVD, etc.According to certain embodiments, a coating 375, which can be a rareearth metal silicate coating or a rare earth metal oxide coating, can beformed over the conformal ALD coating 316 using PVD, PEPVD, etc. Coating375 may have a thickness of about 3 nm to about 250 μm, or about 5 nm to100 μm, or about 5 nm to 50 μm, or about 25 nm to 50 μm, or about 50 nmto 10 μm, or about 50 nm to 5 μm, or about 50 nm to 1 μm, or about 50 nmto about 500 nm, or about 75 nm to about 200 nm. In some embodiments,the materials used to form coating 375 may be the same as the materialsused to form coating 316. In other embodiments, the materials may bedifferent, for example, coating 375 may be a rare earth metal oxide. Inaddition, coatings formed by a line-of-sight approach can be singlelayer or multi-layer (e.g., with one or more rare earth metal containingsilicates or oxide materials).

In other embodiments, the formation of a thick rare earth metalcontaining silicate or oxide layer can first be formed on a particularsurface area of the article (e.g., a body of the article) by aline-of-sight deposition approach. Subsequently, a conformal rare earthmetal containing coating is formed over the entire surface (includingthe coated portion) of the article surface by a non-line-of-sightdeposition approach.

FIG. 4A illustrates a method 400 for forming a rare earth metalcontaining silicate coating on an article (e.g., a susceptor or aheater) or a body of an article according to embodiments. Method 400 maybe used to coat any articles described herein. The method may optionallybegin by selecting a composition for the rare earth metal containingsilicate coating. The composition selection and method of forming may beperformed by the same entity or by multiple entities.

The method may optionally include, at block 405, cleaning the articlewith an acid solution. In one embodiment, the article is bathed in abath of the acid solution. The acid solution may be a hydrofluoric acid(HF) solution, a hydrochloric acid (HCl) solution, a nitric acid (HNO₃)solution, or combination thereof in embodiments.

At block 410, the article is loaded into a deposition chamber.Optionally, at block 425, a deposition process is performed to deposit abuffer layer such as a Si_(x)O_(y) (e.g., SiO₂) layer on the article. Atblock 420, the method comprises depositing a rare earth metal containingsilicate coating onto a surface of the article using at least one of achemical vapor deposition (CVD), plasma enhanced chemical vapordeposition (PECVD), physical vapor deposition (PVD), plasma enhancedphysical vapor deposition (PEPVD), or atomic layer deposition (ALD) orcombinations thereof. At block 430, a deposition process is performed todeposit at least one layer of a rare earth metal containing silicatecoating. The at least one layer may be, for example, a rare earth metalmonosilicate, a rare earth metal disilicate or a rare earth metal oxide.

In one embodiment, optionally, at block 435, another deposition process(or cycle) is performed to deposit at least one additional layer of therare earth metal containing silicate coating. The at least oneadditional layer may be, for example, a rare earth metal monosilicate, arare earth metal disilicate or a rare earth metal oxide.

In one embodiment, the method includes forming a buffer layer on asurface of a body, and forming a multi-layer stack on the buffer layerincluding alternately depositing layers of a rare earth metalmonosilicate and a rare earth metal disilicate on the buffer layer,wherein the rare earth metal of the monosilicate and the disilicateindependently comprises at least one of yttrium, erbium, tantalum,iridium, rhodium, lanthanum, lutetium, scandium, gadolinium, samariumand dysprosium. In some embodiments, a rare earth metal monosilicate isthe final (surface) layer deposited on the body of the article. In otherembodiments, the final (surface) layer deposited on the body of thearticle is a rare earth metal containing oxide selected from yttriumoxide (Y₂O₃), erbium oxide (Er₂O₃), tantalum oxide (Ta₂O₅), iridium(Ir₂O₃), rhodium (Rh₂O₃), lanthanum oxide (La₂O₃), lutetium oxide(Lu₂O₃), scandium oxide (Sc₂O₃), gadolinium oxide (Gd₂O₃), samariumoxide (Sm₂O₃) dysprosium oxide (Dy₂O₃) and combinations thereof.

In further embodiments, the method includes forming a plasma resistantheater or susceptor including performing at least an atomic layerdeposition process to deposit a rare earth metal containing silicatecoating on a surface of the heater or susceptor, wherein the heatercomprises aluminum nitride or wherein the susceptor comprises graphitecoated with silicon carbide, tantalum carbide or a combination thereof,wherein the rare earth metal containing silicate coating has a thicknessof about 3 nm to about 250 μm, and wherein the rare earth metalcontaining silicate coating comprises at least one of yttriummonosilicate (Y₂SiO₅), yttrium disilicate (Y₂Si₂O₇), erbium monosilicate(Er₂SiO₅), erbium disilicate (Er₂Si₂O₇), tantalum monosilicate(Ta₂SiO₅), tantalum disilicate (Ta₂Si₂O₇), iridium monosilicate(Ir₂SiO₅), iridium disilicate (Ir₂Si₂O₇), rhodium monosilicate(Rh₂SiO₅), rhodium disilicate (Rh₂Si₂O₇), lanthanum monosilicate(La₂SiO₅), lanthanum disilicate (La₂Si₂O₇), lutetium monosilicate(Lu₂SiO₅), lutetium disilicate (Lu₂Si₂O₇), scandium monosilicate(Sc₂SiO₅), scandium disilicate (Sc₂Si₂O₇), gadolinium monosilicate(Gd₂SiO₅), gadolinium disilicate (Gd₂Si₂O₇), samarium monosilicate(Sm₂SiO₅), samarium disilicate (Sm₂Si₂O₇), dysprosium monosilicate(Dy₂SiO₅), dysprosium disilicate (Dy₂Si₂O₇) and combinations thereof.

FIG. 4B illustrates a method 450 for forming a rare earth metalcontaining silicate coating on an article (e.g., a susceptor or aheater) or a body of an article according to an embodiment. The methodmay optionally begin by selecting compositions for the rare earth metalcontaining silicate coating. The composition selection and method offorming may be performed by the same entity or by multiple entities.

At block 452 of method 450, a surface of the article optionally may becleaned using an acid solution. The acid solution may be any of the acidsolutions described above with reference to block 405 of method 400. Thearticle may then be loaded into a deposition chamber.

Pursuant to block 455, the method includes depositing a buffer layer(e.g., SiO₂) onto at least one surface of the article via CVD, PECVD,PVD, PEPVD, ALD or combinations thereof. The buffer layer may have athickness of about 5 nm to about 300 nm. Pursuant to block 460, themethod further includes depositing a rare earth metal containing oxidelayer (e.g., Y₂O₃) on the buffer layer also via CVD, PECVD, PVD, PEPVD,ALD or a combination thereof. The rare-earth metal containing oxidelayer may include a mixture of multiple different rare earth metaloxides, for example, Y₂O₃ and Er₂O₃.

At block 470, a determination may be made as to whether additionallayers are to be added (e.g., if a multi-layer stack is to be formed).If additional layers are to be added, then the method may return toblock 455 and an additional layer of Si_(x)O_(y) may be formed.Otherwise the method may proceed to block 475.

At block 475, the article (e.g., the susceptor or heater) and thedeposited layers from blocks 455, 460 and 470 are heated. The heatingmay be via an annealing process, a thermal cycling process and/or via amanufacturing step during semiconductor processing. In one embodiment,thermal cycling process is performed on coupons as a check aftermanufacture to detect cracks for quality control, where the coupons arecycled to the highest temperature that a part may experience duringprocessing. The thermal cycling temperature depends on a specificapplication or applications that the part will be used for. Thetemperature may be selected based on the material of construction of thearticle, surface, and film layers so as to maintain their integrity andrefrain from deforming, decomposing, or melting any or all of thesecomponents.

According to embodiments, when forming a yttrium monosilicate and/or ayttrium disilicate from a multilayer stack containing layers of a rareearth metal containing oxide (e.g., Y₂O₃) and a silicon oxide (e.g.,SiO₂), the ratio of the number of rare earth metal containing oxidedeposition cycles to the number of silicon oxide deposition cycles willaffect the amount of yttrium monosilicates and disilicates in the finalcoating (e.g., a solid solution containing multiple phases). Forexample, a 2:1 ratio of the number of Y₂O₃ to the number of SiO₂deposition cycles will result in Y₂SiO₅.

Yttrium containing precursors useful in the methods disclose hereininclude, but are not limited to,tris(N,N-bis(trimethylsilyl)amide)yttrium (III) and yttrium(III)butoxide precursor. In some embodiments, two different rare earthmetal containing precursors (e.g., a yttrium containing precursor and asilicon containing precursor) can be co-deposited onto the article orthe body of the article. For example, the two precursors may beintroduced into the process chamber together or sequentially before thereactant is introduced.

The rare earth metal containing silicate coatings described hereinresist thermal oxidation and erosion at temperatures of about 25° C. toabout 1,500° C. The resistance of the rare earth metal containingsilicate coating to plasma can be measured through “erosion rate” (ER),which may have units of micron/hour (μm/hr) or Angstrom/hour (Å/hr),throughout the duration of the coated components' operation and exposureto plasma. Measurements may be taken after different processing timesand/or temperatures. For example, measurements may be taken beforeprocessing, or at about 50 processing hours, or at about 150 processinghours, or at about 200 processing hours, and so on. Variations in thecomposition of the rare earth metal containing silicate coating grown ordeposited on the heater support and/or other components may result inmultiple different plasma resistances or erosion rate values.Additionally, a rare earth metal containing silicate coating with asingle composition exposed to various plasmas could have multipledifferent plasma resistances or erosion rate values. For example, aplasma resistant material may have a first plasma resistance or erosionrate associated with a first type of plasma and a second plasmaresistance or erosion rate associated with a second type of plasma.

EXAMPLES Example 1—Deposition of Y_(x)Si_(y)O_(z) Coatings on aSubstrate Using ALD

Yttrium silicate (Y_(x)Si_(y)O_(z)) coatings were deposited ontosubstrates (i.e., silicon wafers) using ALD according to embodimentsdescribed herein. The yttrium containing precursor used to form thecoatings was (MeCp)₃Y+H₂O and the silicon containing precursor wasbis(tertiary-butylamino)silane (BTBAS)+O₃. The resulting thickness ofthe rare earth metal containing coatings was 100 nm. Each resultantcoating was a single layer Y_(x)Si_(y)O_(z) coating containing Y₂Si₂O₇or Y₂SiO₅. A Transmission Electron Microscopy (TEM) spectrum showed thatthe composition distribution of the 100 nm Y₂Si₂O₇ coating containedoxygen (O) at an atomic concentration of about 65%, yttrium (Y) at anatomic concentration of about 20% and silicon (Si) at an atomicconcentration of about 18%. A TEM spectrum showed that the compositiondistribution of the 100 nm Y₂SiO₅ coating contained oxygen (O) at anatomic concentration of about 62%, yttrium (Y) at an atomicconcentration of about 30% and silicon (Si) at an atomic concentrationof about 10%. The coatings conformally coated the silicon wafersubstrates. A 500 nm Y₂Si₂O₇ coating was also deposited using ALD onsilicon carbide (SiC) formed by chemical vapor deposition. The 500 nmY₂Si₂O₇ coating conformally covered the SiC layer.

Additionally, a 5 μm Y₂Si₂O₇ coating was deposited using ion assisteddeposition (IAD) on an alumina (Al₂O₃) ceramic substrate. The 5 μmY₂Si₂O₇ coating adhered to the alumina ceramic substrate.

Another 100 nm Y₂Si₂O₇ coating was deposited by ALD onto an uneven SiClayer that was deposited by CVD. The coating had very good coverage andadhesion to the uneven SiC layer and no cracks or defects were observedon the coating body and/or interfacial area.

A nine (9) μm amorphous YF₃ coating was deposited by IAD over a 500 nmY₂Si₂O₇ deposited by ALD on an Al6061 substrate. The coating had goodcoverage and adhesion to the yttrium silicate layer and no cracks ordefects were observed on the coating body and/or interfacial area.

Example 2—Temperature Resistance of Y₂SiO₅ Coatings

Three samples were prepared: 1) Y₂SiO₅ was deposited by ALD on a SiClayer deposited by CVD; 2) Y₂SiO₅ was deposited by ALD on an Al₂O₃substrate; and Y₂SiO₅ was deposited by ALD on a silicon wafer. Thesamples were exposed to a heat treatment process including a ramp up to350° C. where the temperature was maintained for 10 minutes and then to750° C. for 2 hours; subsequently, the temperature was ramped down to350° C. for 10 minutes and then to 40° C. Scanning Electron Microscopy(SEM) images were taken for each of the coatings both before and afterthe heat treatment. For all of the coatings there were no measurablechanges in surface morphology and no observable cracks or defects. Thedata demonstrated that Y₂SiO₅ material provides a stable structure forcoatings on different types of substrates.

Example 3—Plasma Resistance of Y₂SiO₅ Coatings

Three samples were prepared: 1) a SiC layer deposited by CVD on asubstrate; 2) Y₂O₃ deposited by ALD on an aluminum nitride (AlN)substrate; and Y₂SiO₅ deposited by ALD on a SiC layer deposited by CVD.All samples were placed in an AlN heater a temperature of 650° C. andexposed to an oxygen (O₂) plasma for 41 hours. Scanning ElectronMicroscopy (SEM) images were taken for each of the samples both beforeand after the heat treatments. The CVD SiC sample 1) showed erosion as aresult of the hot O₂ plasma process. For the Y₂SiO₅ on SiC sample 3),there was no measurable change in surface morphology and no observablecracks or defects. Additional samples were prepared for Y₂SiO₅ depositedon an AlN substrate and Y₂Si₂O₅ deposited on AlN and CVD SiC substrates.For all of these additional samples, the SEM results showed the samestructural stability of the coatings throughout the hot O₂ plasmaprocess.

The preceding description sets forth numerous specific details such asexamples of specific systems, components, methods, and so forth, inorder to provide a good understanding of several embodiments of thepresent invention. It will be apparent to one skilled in the art,however, that at least some embodiments of the present invention may bepracticed without these specific details. In other instances, well-knowncomponents or methods are not described in detail or are presented insimple block diagram format in order to avoid unnecessarily obscuringthe present invention. Thus, the specific details set forth are merelyexemplary. Particular implementations may vary from these exemplarydetails and still be contemplated to be within the scope of the presentinvention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.In addition, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or.” When the term “about” or “approximately” is usedherein, this is intended to mean that the nominal value presented isprecise within ±10%.

Although the operations of the methods herein are shown and described ina particular order, the order of the operations of each method may bealtered so that certain operations may be performed in an inverse orderor so that certain operation may be performed, at least in part,concurrently with other operations. In another embodiment, instructionsor sub-operations of distinct operations may be in an intermittentand/or alternating manner.

It is to be understood that the above description is intended to beillustrative, and not restrictive. Many other embodiments will beapparent to those of skill in the art upon reading and understanding theabove description. The scope of the invention should, therefore, bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled.

What is claimed is:
 1. A method comprising: performing a deposition process to deposit a rare earth metal containing silicate coating on a surface of a chamber component for a processing chamber, wherein the rare earth metal containing silicate coating has a thickness of about 5 nm to about 250 μm, and optionally, performing a PVD or PEPVD deposition process to deposit a thick rare earth metal silicate layer above or below the rare earth metal containing silicate coating, and wherein the rare earth metal containing silicate coating comprises at least one of yttrium monosilicate (Y₂SiO₅), yttrium disilicate (Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅), erbium disilicate (Er₂Si₂O₇), tantalum monosilicate (Ta₂SiO₅), tantalum disilicate (Ta₂Si₂O₇), iridium monosilicate (Ir₂SiO₅), iridium disilicate (Ir₂Si₂O₇), rhodium monosilicate (Rh₂SiO₅), rhodium disilicate (Rh₂Si₂O₇), lanthanum monosilicate (La₂SiO₅), lanthanum disilicate (La₂Si₂O₇), lutetium monosilicate (Lu₂SiO₅), lutetium disilicate (Lu₂Si₂O₇), scandium monosilicate (Sc₂SiO₅), scandium disilicate (Sc₂Si₂O₇), gadolinium monosilicate (Gd₂SiO₅), gadolinium disilicate (Gd₂Si₂O₇), samarium monosilicate (Sm₂SiO₅), samarium disilicate (Sm₂Si₂O₇), dysprosium monosilicate (Dy₂SiO₅), dysprosium disilicate (Dy₂Si₂O₇) and combinations thereof.
 2. The method of claim 1, wherein the deposition process comprises at least one of chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), plasma enhanced physical vapor deposition (PEPVD) and atomic layer deposition (ALD).
 3. The method of claim 1, further comprising: forming a buffer layer on the surface of the chamber component prior to performing the deposition process to deposit the rare earth metal containing silicate coating on the surface of the chamber component.
 4. The method of claim 1, wherein forming the rare earth metal containing silicate coating comprises: forming a multi-layer stack by alternately depositing layers of a rare earth metal monosilicate and a rare earth metal disilicate, wherein the rare earth metal monosilicate comprises at least one of Y₂SiO₅, Er₂SiO₅, Ta₂SiO₅, Ir₂SiO₅, Rh₂SiO₅, La₂SiO₅, Lu₂SiO₅, Sc₂SiO₅, Gd₂SiO₅, Sm₂SiO₅ and Dy₂SiO₅, and wherein the rare earth metal disilcate comprises at least one of Y₂Si₂O₇, Er₂Si₂O₇, Ta₂Si₂O₇, Ir₂Si₂O₇, Rh₂Si₂O₇, La₂Si₂O₇, Lu₂Si₂O₇, Sc₂Si₂O₇, Gd₂Si₂O₇, Sm₂Si₂O₇ and Dy₂Si₂O₇.
 5. The method of claim 1, further comprising coating the rare earth metal silicate layer with a rare earth metal containing oxide coating, wherein the rare earth metal containing oxide comprises at least one of yttrium oxide (Y₂O₃), erbium oxide (Er₂O₃), tantalum oxide (Ta₂SiO₅), iridium oxide (Ir₂O₃), rhodium oxide (Rh₂O₃), lanthanum oxide (La₂O₃), lutetium oxide (Lu₂O₃), scandium oxide (Sc₂O₃), gadolinium oxide (Gd₂O₃), samarium oxide (Sm₂O₃), dysprosium oxide (Dy₂O₃) and combinations thereof.
 6. The method of claim 1, wherein forming the rare earth metal containing silicate coating comprises: depositing a multi-layer stack by alternately depositing layers of Y₂O₃ and SiO₂, and annealing the multi-layer stack to form at least one of: a) a solid phase of a rare earth metal monosilicate or a solid phase of a rare earth metal disilicate, b) a double phases of a rare earth metal monosilicate and a rare earth metal disilicate, c) a mixed phase material of a rare earth metal monosilicate, yttria and silica, d) a mixed phase material of a rare earth metal disilicate, yttria and silica, and e) a mixed phase material of a rare earth metal monosilicate, a rare earth metal disilicate, yttria and silica.
 7. The method of claim 6, wherein depositing the multi-layer stack comprises: depositing at least one Y₂O₃ layer using precursors of tris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide, tris(cyclopentadienyl)yttrium(III), or Y(thd)3 (thd=2,2,6,6-tetramethyl-3,5-heptanedionato) and a reactant comprising at least one of O₂, H₂O and O₃, and depositing at least one SiO₂ layer using precursors of as silane, dichlorosilane, 2,4,6,8-tetramethylcyclotetrasiloxane, dimethoxydimethylsilane, disilane, methylsilane, octamethylcyclotetrasiloxane, tris(isopropoxy)silanol, tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol and a reactant comprising at least one of O₂, H₂O and O₃.
 8. The method of claim 7, wherein each of the alternating layers in the multi-layer stack has a thickness of about 3 nm to about 300 nm.
 9. A method comprising: performing an atomic layer deposition process to deposit a rare earth metal containing silicate coating on a surface of a heater comprising aluminum nitride or a susceptor comprising graphite coated with silicon carbide, tantalum carbide or a combination thereof and optionally, performing a PVD or PEPVD deposition process to deposit a thick rare earth metal silicate layer above or below the rare earth metal containing silicate coating, wherein the rare earth metal containing silicate coating has a thickness of about 3 nm to about 20 μm, and wherein the rare earth metal comprises at least one of yttrium erbium, tantalum, iridium, rhodium, lanthanum, lutetium, scandium, gadolinium, samarium, dysprosium, and combinations thereof.
 10. The method of claim 9, further comprising: forming a buffer layer on the surface of the heater prior to performing the atomic layer deposition process to deposit the rare earth metal containing silicate coating on the surface of the heater.
 11. The method of claim 9, wherein forming the rare earth metal containing silicate coating comprises: forming a multi-layer stack by alternately depositing layers of a rare earth metal monosilicate and a rare earth metal disilicate, wherein the rare earth metal monosilicate comprises at least one of Y₂SiO₅, Er₂SiO₅, Ta₂SiO₅, Ir₂SiO₅, Rh₂SiO₅, La₂SiO₅, Lu₂SiO₅, Sc₂SiO₅, Gd₂SiO₅, Sm₂SiO₅ and Dy₂SiO₅, and wherein the rare earth metal disilcate comprises at least one of Y₂Si₂O₇, Er₂Si₂O₇, Ta₂Si₂O₇, Ir₂Si₂O₇, Rh₂Si₂O₇, La₂Si₂O₇, Lu₂Si₂O₇, Sc₂Si₂O₇, Gd₂Si₂O₇, Sm₂Si₂O₇ and Dy₂Si₂O₇.
 12. The method of claim 9, further comprising coating the rare earth metal silicate layer with a rare earth metal containing oxide coating, wherein the rare earth metal containing oxide comprises at least one of yttrium oxide (Y₂O₃), erbium oxide (Er₂O₃), tantalum oxide (Ta₂SiO₅), iridium oxide (Ir₂O₃), rhodium oxide (Rh₂O₃), lanthanum oxide (La₂O₃), lutetium oxide (Lu₂O₃), scandium oxide (Sc₂O₃), gadolinium oxide (Gd₂O₃), samarium oxide (Sm₂O₃), dysprosium oxide (Dy₂O₃) and combinations thereof.
 13. The method of claim 9, wherein forming the rare earth metal containing silicate coating comprises: depositing a multi-layer stack by alternately depositing layers of Y₂O₃ and SiO₂; and annealing the multi-layer stack to form at least one of: a) a solid phase of a rare earth metal monosilicate or a solid phase of a rare earth metal disilicate, b) a double phases of a rare earth metal monosilicate and a rare earth metal disilicate, c) a mixed phase material of a rare earth metal monosilicate, yttria and silica, d) a mixed phase material of a rare earth metal disilicate, yttria and silica, and e) a mixed phase material of a rare earth metal monosilicate, a rare earth metal disilicate, yttria and silica.
 14. The method of claim 13, wherein depositing the multi-layer stack comprises: depositing at least one Y₂O₃ layer using precursors of tris(N,N-bis(trimethylsilyl)amide)yttrium (III), yttrium (III)butoxide, tris(cyclopentadienyl)yttrium(III), or Y(thd)3 (thd=2,2,6,6-tetramethyl-3,5-heptanedionato) and a reactant comprising at least one of O₂, H₂O and O₃, and depositing at least one SiO₂ layer using precursors of as silane, dichlorosilane, 2,4,6,8-tetramethylcyclotetrasiloxane, dimethoxydimethylsilane, disilane, methylsilane, octamethylcyclotetrasiloxane, tris(isopropoxy)silanol, tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol and a reactant comprising at least one of O₂, H₂O and O₃.
 15. The method of claim 14, wherein each of the alternating layers in the multi-layer stack has a thickness of about 3 nm to about 300 nm.
 16. A method comprising: performing a deposition process to deposit a rare earth metal containing silicate coating on a surface of a chamber component for a processing chamber, wherein the rare earth metal containing silicate coating has a thickness of about 3 nm to about 250 μm; and performing a PVD or PEPVD deposition process to deposit a thick rare earth metal silicate layer above or below the rare earth metal containing silicate coating, wherein the rare earth metal containing silicate coating comprises at least one of yttrium monosilicate (Y₂SiO₅), yttrium disilicate (Y₂Si₂O₇), erbium monosilicate (Er₂SiO₅), erbium disilicate (Er₂Si₂O₇), tantalum monosilicate (Ta₂SiO₅), tantalum disilicate (Ta₂Si₂O₇), iridium monosilicate (Ir₂SiO₅), iridium disilicate (Ir₂Si₂O₇), rhodium monosilicate (Rh₂SiO₅), rhodium disilicate (Rh₂Si₂O₇), lanthanum monosilicate (La₂SiO₅), lanthanum disilicate (La₂Si₂O₇), lutetium monosilicate (Lu₂SiO₅), lutetium disilicate (Lu₂Si₂O₇), scandium monosilicate (Sc₂SiO₅), scandium disilicate (Sc₂Si₂O₇), gadolinium monosilicate (Gd₂SiO₅), gadolinium disilicate (Gd₂Si₂O₇), samarium monosilicate (Sm₂SiO₅), samarium disilicate (Sm₂Si₂O₇), dysprosium monosilicate (Dy₂SiO₅), dysprosium disilicate (Dy₂Si₂O₇) and combinations thereof.
 17. The method of claim 16, wherein the chamber component comprises a material selected from the group consisting of aluminum nitride, graphite, silicon carbide, tantalum carbide and combinations thereof.
 18. The method of claim 16, wherein the chamber component is a heater or a susceptor for a processing chamber.
 19. The method of claim 16, wherein the chamber component comprises a material having a coefficient of thermal expansion (CTE) of about 4.0×10⁻⁶/K to about 6.5×10⁻⁶/K and wherein the rare earth metal containing silicate coating on the surface of the body has a CTE of about 4.5×10⁻⁶/K to about 7.0×10⁻⁶/K.
 20. The method of claim 16, wherein the rare earth metal containing silicate coating comprises a rare earth metal monosilicate and a rare earth metal disilicate at a volume ratio (monosilicate:disilicate) of about 1:20 to about 20:1. 